This is a follow up study to evaluate the neurodevelopmental status of children with pulmonary hypertension at birth who were enrolled in the randomized trial of inhaled nitric oxide. Study staff will schedule a follow-up visit with the parent. The visit will take approximately 2-3 hours. During the visit, the infant will have a neurological, developmental, and physical exam performed by a pediatrician. Parents will be asked questions about their child's developmental, demographic, and medical history, and behavior. Infants with persistent pulmonary hypertension are known to be at risk for adverse health and neurodevelopmental outcomes. Assessment of health and neurodevelopmental outcome of the enrolled patients in the previous protocol is crucial as the effectiveness of nitric oxide is further defined.